We propose a postdoctoral Program to provide research training in medical genetics. The primary objective of the program is the training of physicians in research in medical genetics, to enable them to become independent investigators, and academic and scientific leaders in human genetic disease. An especial and unique strength of the Program is the integration of clinical and research activities in medical genetics at UCSF, resulting in the interactions of research trainees with trainees and faculty in clinical genetics. Research trainees are thereby provided with the broadest possible background upon which to formulate and develop future research problems. The major component (about 80%) of the Training Program is the conduct of a clearly defined and substantive research project under the supervision of a Program Faculty investigator. The Training Faculty includes investigators from both clinical and basic science departments. The research activities of the Training Faculty are truly diverse, and include basic, clinical laboratory, and epidemiologic research in: biochemical genetics, cancer genetics, cardiovascular developmental genetics, fetal development and birth defects, gene therapy, the genetics of complex disorders, the genetics of deafness, genodermatoses, genomics and informatics, hemoglobinopathies, immunogenetics, liver disease, lipoprotein disorders, molecular cytogenetics, pharmacogenetics, sex chromosome biology, and mammalian, Drosophila and zebra fish developmental genetics. Faculty members of this Training Program have an excellent record in pre-and post-doctoral training in genetics, impressive laboratory facilities, and extensive funding for their research. This faculty can therefore provide the space, laboratory resources, and programmatic environments for the successful research training of postdoctoral trainees under this Program. Additional components of the Training Program include attendance at scheduled research and medical genetics conferences; graduate level courses in research methodology and in basic genetics and advanced human genetics; and targeted instruction in clinical and clinical laboratory genetics. The vast majority of applicants and entrants are physicians (MD or MD-Ph.D.)) interested in research careers in medical genetics. The Program has also been able to accommodate scientists (Ph.D.) interested in research, teaching, and clinical laboratory careers in medical genetics. The Program is overseen at UCSF by a Program Director and an Advisory Group, who regularly evaluates and monitors the progress of trainees. Finally, the Program will immeasurably benefit from the current commitment to the broad expansion and enhancement of the academic presence of human genetics at UCSF.